Boot up Navigatrix and open a terminal and enter:
sudo photorecFollow the instructions....if in doubt enter:
man photorecbeforehand for the manual. These manuals tend to be dense so if you don't understand what's going on checkout
http://www.cgsecurity.org/wiki/PhotoRec_Step_By_Step...straight from the horse's mouth.
Good luck.
16GB is the same as the 8GB...which is the same as the 4GB version. What changes is the size of the persistent files 'root" and "home".
If you are just storing data (music, downloads, pictures, videos); you don't have to change anything.
However, if you are going to add additional software applications you might want to increase thes size of those persistent files. Take a look at
http://navigatrix.net/viewtopic.php?f=6&t=357People who need/want more space/performance should consider a hard drive installation.